Fig. 5

Hawk tea extract (HTE) inhibits Niemann–Pick C1-like 1 (NPC1L1)-mediated free cholesterol uptake. a The effect of 25-hydroxycholesterol (25-HC) (0.5 μg mL⁻¹) on the stimulatory effects of HTE (200 μg mL⁻¹) on low-density lipoprotein receptor (LDLR) and other sterol response element binding protein 2 (SREBP2) downstream genes (SREBP2, HMGCS1, HMGCR, and FPP) in HepG2 cells (n = 3). b Time course of HTE (200 μg mL⁻¹) effect on cellular total cholesterol level in HepG2 cells (n = 3). c Representative flow cytometry analysis of NBD (22-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)-labeled free cholesterol uptake and d quantitative analysis of free cholesterol uptake by HepG2 cells under HTE (200 μg mL⁻¹) or Ezetimibe (50 μΜ) treatment for different time durations (n = 3). The mean fluorescence intensity (MFI) at different time points indicates the amount of NBD-labeled free cholesterol uptake by HepG2 cells. NBD-cholesterol was delivered to cells in ethanol. The MFI of untreated cells was set as 100%. e Representative flow cytometry analysis of NBD-labeled free cholesterol uptake under HTE (200 µg mL⁻¹) treatment for 1 h and quantitative analysis of free cholesterol uptake by Caco2 cells (n = 3). f Cholesterol-regulated NPC1L1 translocation between the plasma membrane and endocytic recycling compartment (ERC) in CRL1601/NPC1L1-EGFP cells. The green fluorescence signals indicate the distribution of NPC1L1 protein. g The effect of HTE on the translocation of NPC1L1 from plasma membrane to ERC in CRL1601/NPC1L1-EGFP cells. Cells were treated as shown in the diagram (HTE: 100 μg mL⁻¹; Ezetimibe: 50 μΜ). Scale bar = 20 μm. The green fluorescence signals indicate the distribution of NPC1L1 protein and the arrows indicate the localization of plasma membrane. Data are shown in mean ± SD. Statistical analyses were conducted using paired Student’s t test. *p < 0.05; **p < 0.01; ns: not significant. Filled circles indicate the individual data points of each independent experiments under the indicated treatment conditions